Layered Li ((NixMnyCoz) O2における熱安定性の調節について
Jiaxin Zheng1, Tongchao Liu1, Zongxiang Hu1
1School of Advanced Materials, Peking University, Shenzhen Graduate School , Shenzhen 518055, People's Republic of China.
Journal of the American Chemical Society
|September 20, 2016
まとめ
リチウム・ニッケル・マンガン・コバルト酸化物 (NMC) 材料の熱安定性を最適化することは,電気自動車のバッテリーにとって重要なことです. この研究は,酸素が
科学分野:
- 材料科学
- 電気化学
- コンピュータ化学
背景:
- リチウム・ニッケル・マンガン・コバルト酸化物 (NMC) 材料は,電気自動車 (EV) を動かすリチウムイオンバッテリー (LIB) に不可欠です.
- NMCカトードの熱安定性を最適化することは,バッテリーの安全性と性能を高めるために不可欠です.
研究 の 目的:
- NMC 材料の熱安定性を制御するメカニズムを解明する.
- 局所調整構造ユニット (LCSU) での酸素の役割を理解することによって,熱安定を調節するためのモデルを確立する.
主な方法:
- 実験的な検証と組み合わせた 初期計算を用いる.
- 酸素の局所調整構造単位 (LCSU),特にTM ((Ni, Mn, Co) 3-O-Li3-x') を分析して,酸素結合と安定性を理解する.
主要な成果:
- LCSU内の最も不安定な酸素原子によって直接影響されます.
- リチウムの含有量,Niバレンスの状態,元素組成 (Ni,Mn,Co),Ni/Li障害は酸素の場所,含有量,および放出温度に大きな影響を与える.
- Liの空白と高いNi値の状態の間の相乗効果は酸素の不安定性を悪化させ,LCSUのより高いNi含有量はより不安定な酸素につながります.
結論:
- 酸素の局所環境と安定性を制御することによって,NMCの熱安定性を調整するための予測モデルが提案されています.
- Ni/Liの混合効果を理解することは極めて重要です:それは"Ni=Mn"の群の安定性を低下させますが,スーパー交換チェーンを形成することによって"Ni=Mn"のNMCの安定性を高めます.
- MnとCoドーピングは,Niバレンスの状態,酸素調整,Ni/Li障害を修正することによって,NMCの熱安定性を調節する直接的な経路を提供します.
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